A total of 4/5 genes that were significantly associated with SUVmax in our EwS cohort have functions regarding stemness or differentiation: FAXDC2 plays a role in megakaryocyte differentiation; NETO2 activates tumorigenic, stemness-related signaling pathways [89,90]; ELOVL2 is upregulated in glioma stem cells in glioblastoma, which is mediated by stem cell enhancers like SOX2 [91]; MYBL2 maintains an undifferentiated state of cells [92]. This evidence concerns the gene FAXDC2 and central nervous system cancer.